mfd: Remove tps6586x device ID check

... and convert it to a dev_info print at probe time.

There are many variants of this chip with different values of VERSIONCRC.
The set of values is large, and not useful to enumerate. All are SW
compatible. The difference lies in default settings of the various power
rails, and other similar differences. The driver, or clients of the
driver, shouldn't be affected by this, since all rails should be
programmed into the desired state in all cases for correct operation.

Derived-from-code-by: Andrew Chew <achew@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>